ABSTRACT In many sub-Saharan African countries, the scale-up of lifelong antiretroviral treatment (ART) to all pregnant and breastfeeding women under Option B+ has the potential to radically improve maternal health and reduce mother-to-child HIV transmission. However, loss to HIV care after delivery has emerged as an important threat to the hoped-for impact of Option B+. Evidence suggests that one important contributor to postpartum loss to HIV care is perinatal depression (PND). PND affects up to 43% of HIV-infected women during pregnancy and 31% of HIV-infected women postpartum. In non-pregnant HIV-infected populations, depression has been linked to poor ART adherence, reduced engagement in care, and ultimately worse HIV clinical outcomes. Thus, interventions that integrate PND treatment with targeted support for HIV care retention are critical to the success of Option B+. The Friendship Bench is an evidence-based depression counseling intervention delivered by trained, supervised lay health workers. The Friendship Bench is proven to reduce depression in the general population in low-resource settings, but has not been adapted to address PND, or enhanced to support engagement in HIV care. The Friendship Bench is based on problem-solving therapy, which offers an ideal framework for integrating retention support into a proven depression treatment model. Our long-term goal is to adapt, test, and scale up resource-appropriate interventions to reduce PND and improve engagement in HIV care. The objective of this proposal is to lay the groundwork for an effectiveness trial by (1) adapting the Friendship Bench intervention to address PND and support engagement in care among perinatal HIV-infected women and (2) assessing the feasibility, acceptability, and fidelity of the adapted intervention. The proposed project will take place in Lilongwe, Malawi, where Option B+ was first piloted in 2011. In-depth perspectives on PND and its role in engagement in care will be gathered from HIV-infected women with PND, healthcare providers, clinic directors, and Ministry of Health officials using qualitative interviews and focus groups. This formative research will be used to develop an intervention protocol adapted to the unique needs of HIV-infected women during the perinatal period (Adapted Friendship Bench) and further enhanced to support engagement in HIV care (Enhanced Friendship Bench). The Adapted and Enhanced Friendship Bench interventions will be compared to enhanced standard care in a 3-arm pilot study. Feasibility, acceptability, and fidelity will be assessed at 6 months postpartum, along with the interventions' preliminary effectiveness across several mental health and engagement in HIV care measures. The proposed aims pave the way for a R01 application to test the adapted and enhanced Friendship Bench interventions in a cluster randomized controlled trial and represent an important step forward towards improving PND among HIV-infected women, and ultimately HIV outcomes for women in the Option B+ program.